Piano.



A. A. HUSEBY PIANO.

APPLIUATION FILED MAY15, 1911.

1,008,269. Ptentea Nov. 7,1911.

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COLUMBIA PMNOGRAPH C0., WASHXNUTVON. D. C.

A. A. HUSEBY.

Patented Nov. 7, 1911.

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PIANO.

Specification of Letters Patent.

Application filed May 15, 1911. Serial No. 627,246.

To all whom it may concern:

Be it known that I, ALBERT A. HUSEBY, a citizen of the United States, residing at Chicago, county of Cook, and State of Illi nois, have invented certain new and useful Improvements in Pianos, of which the following is a specification.

My invention relates to pianos, and has reference more particularly to improvements in that class of pianos employing a double sounding board.

The main object of the invention is to provide a thoroughly practical and eiiicient piano construction of the double sounding board type which shall increase the power and volume, and enhance the tone quality of such instrument, as well as simplify the construction to a considerable extent through the elimination of all ofthe usual back frame of the instrument except the outer or bounding portion thereof, for which latter purpose the string-plate, in my improved construction, is made of sufficient size and strength to furnish the rigidity necessary to with stand the great tension of the strings.

My invention, its novel structural features, and the advantages inhering therein will all be readily understood when considered in connection with the accompanying drawings, which show one practical form in which the invention may be embodied, and in which- Figure 1 is a rear elevation of my improved piano. Fig. 2 is a cross section of the same on the line 2-2 of Fig. 1. Fig. 3 is a rear elevation with the back sounding board removed and part-s of the framing in vertical section. Fig. A is a vertical crosssection on the line 1f-4 of Fig. 1.

Referring to the drawings, 5 and 6 designate the upper and lower transverse bars of the bounding portion of the back frame, and 7 the vertical side bars thereof.

8 designates an immediate horizontal frame bar secured to and extending between the side bars 7 a short distance below the upper frame bar 5, said bar 8 being provided with a series of vertical holes 9 formed therethrough for a purpose hereinafter disclosed.

10 designates a short diagonal frame bar extending between the intermediate bar 8 and one of the side bars 7, and provided with a similar series of holes 11.

12-designates the main or inner sounding board that is glued at its edges to the inner sides of the frame bars 6, 7, and 8, and carries the usual treble and bass bridges 13 and 141, respectively, which project through openings in the skeleton string-plate 15, which latter overlies the sounding board 12, and, in this instance, is of substantially the full height and width of the back frame, and is sufficiently heavy to supply the necessary rigidity to the back frame without requiring the presence of the heavy intermediate vertical members or posts of the usual back frame.

Between the upper parallel frame bars 5 and 8 and behind the upper edge of the string-plate 15 is the usual wrest-plank 16 Patented Nov. 7, 1911. i

which also forms an inner cover plate; and v secured to and between the outer sides of the bars 5 and 8 is an outer cover-plate 17, whereby there is formed between the bars 5, 7 and 8 and the cover plates 16 and 17 an auxiliary resonance chamber 18 which communicates with the space between the two sounding boards through the openings 9 of the bar 8. The cover-plate 17 is formed with a pair of scroll-shaped Openings 19 to permit the escape of the sound waves from the chamber 18.

Glued at its edges to the frame bars 6, 7, and 8 is the outer or auxiliary sounding board 20, which latter is preferably provided with a circular aperture 20iL to permit the escape of the sound waves from the space between the two sounding boards. The back side of the main sounding board 12 is provided with a series of oblique stiffening ribs 21, and the back side of the auxiliary sounding board 20 is likewise provided witha lesser number of similarly disposed stiffening ribs 22; and on the inner side of the sounding board 20 is a single straight oblique bar 23 that has the same general direction as the curved bridge 13 of the front sounding board, the bridge 13 intersecting near its middle point'the plane passing through the bar 28 and transverse to the sounding-board. Between the two sounding-boards and located at the point of intersection is snugly fitted a sound-post 24.

I have found by repeated experiments that the described construction of double sounding board, employing a single sound post located substantially centrally of and between but not connected to the two sounding boards, with one or more openings in the outer or auxiliary sounding board, and with the space between said sounding boards wholly unobstructed except for the presence of said single sound post, has the etect of greatly enhancing the power, volume, and resonance qualities of the instrument, and prolonging the periods through which the tones are audible. The auxiliary resonance chamber 18, also, not only contributes to the above mentioned qualities, but also has the effect of mellowing the sound and enhancingi'ts musical quality.

I am aware that the feature of a double sounding' board in a piano is, broadly, old; but, so far as I am aware, a double sounding board construction which omits the usual intermediate back framing, and secures the `back sounding board directly to the bounding or marginal portion of the back frame, thereby providing a resonance chamber that is wholly unobstructed except for the presence `of a single sound post between the two sounding boards, is new. In other minor structural respects, which I have found by experiment to be of importance in securing` t-he desired improvement in the tone qualitiesof t-he instrument, all as set forth in the appended claims, the described construction is also new.

It `is obvious that the particular number and forms of the opening or openings in the rear walls of the main and auxiliary resonance chambers are not of the essence of the invention, but may be varied as desired.

I claim-- 1. A piano having a back frame, a main sounding board secured to the inner side of said frame, a string-plate secured to the same side of said frame over said main sounding board, an auxiliary sounding board secured to the outer side of said frame, yand a single sound post between said sounding boards, the space within said frame and between said sounding` boards being unobstructed except for the presence of said sound-post, substantially as described.

2. A piano having a back frame, a main sounding board secured to the inner side oit said frame, a string-plate secured to the same side of said trame over said main sounding board, an auxiliary sounding board secured to the outer side of said frame, said auxiliary sounding board having a `bar extending across its inner side, and a single sound-post set between said bar and said main sounding board, the space within said frame and between said sounding boards being unobstructed except for the presence of said sound-post, substantially as described.

3. A piano having a back frame, a main sounding board secured to the inner side of said frame, a string plate secured to the same side of said frame over said main sounding board, an auxiliary sounding board secured to the outer side of said trame, said auxiliary sounding board having a bar extending across its inner side and a series ot' reinforcing ribs on its outer side, and a single sound-post set between said bar and said main sounding-board, the space within said frame and between said sounding boards being unobstructed except for the presence of said sound-post, substantially as described.

4. A piano having a back frame, a main sounding-board secured to the inner side of said frame and provided with a string bridge, a string-plate secured to the same side of said frame over said main soundingboard, an auxiliary sounding-board secured to the outer side of said frame, said auxiliary sounding-board having a bar extending across its inner side, said bridge intersecting near its middle point the plane passing through the said bar and transverse to the sounding-board, and a single sound-post snugly fitted between the two soundingboards at said point of, intersection, the space within said frame and between said sounding-boards being unobstructed except for the presence of said sound-post, substantially as described.

5. A piano having a back frame comprising vertical side bars, upper and lower transverse bars, and an intermediate t-ransverse bar secured to and extending between said side bars a short distance below the upper transverse bar, said intermediate transverse bar having a series of vertical holes formed therethrough, inner and outer sounding boards secured at their edges to the inner and outer sides, respectively, of the frame structure formed by said side bars and intermediate and lower transverse bars, and forming therewith a main resonance chamber, and cover plates secured to the inner and outer sides, respectively, of the frame structure formed by said side bars and intermediate and Lipper transverse bars, and forming therewith an auxiliary resonance chamber communicating with said main resonance chamber through the holes in said intermediate transverse bar, substantially as described.

6. A piano having a back frame comprising vertical side bars, upper and lower transverse bars, and an intermediate transverse bar secured to and extending between said side bars a short distance below the upper transverse bar, said intermediate transverse bar having a series of vert-ical holes formed therethrough, inner and outer sounding boards secured at their edges to the inner and outer sides, respectively, of the frame structure formed by said side bars and intermediate and lower transverse bars, and forming therewith a main resonance chamber, a single sound post :between said sounding boards, and cover plates secured to the inner and outer sides, respectively, of

the frame structure formed by said side bars chambers being formed With openings thereand intermediate and upper transverse bars, in, substantially as described.

and forming therewith an auxiliaryv resonance chamber communicating With said ALBERT A' HUSEBY' main resonance chamber through the holes Witnesses:

in said intermediate transverse bar, the rear SAMUEL N. POND,

Walls of said main and auxiliary resonance DAISY C. THORSEN.

Copies of this Ypatent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

